It is not just in the mind of psychiatrist Martin Dysart that ancient Greece casts a long shadow. The curved blocks which surround the small acting arena in which the story of Equus plays out might be those of an agora, a market-place for both discussion and trial. Horse-head masks like the helmets of Homeric warriors loom over it from high poles. Designer Kerry Bradley has done very well by her director Michael Cabot and his cast.

That has had changes since the production began its tour last autumn. Stuart Angell is now the young horseman who befriends a young Alan Strang on the beach as well as Nugget, the chestnut whose relationship with Alan is the bleeding heart of the play. As the horse, Angell takes us seamlessly into an equine world with subtle body and foot movements which blur, centaur-like, man into beast.

As Alan Matthew Pattimore is completely, one might say agonisingly, credible. He’s well matched by Helen Phillips as Jill, whose well-intentioned initiation of Alan into adulthood goes so disastrously wrong. Malcolm James presents a slow-burn portrait of Dysart and Alan’s parents, so unalike and mismatched in their beliefs and attitudes, are more than peripheral figures. Steve Dineen is atheist socialist Frank and Joanna Waters church-going teacher Dora.

Just as the chorus in classic Greek drama is onstage bearing witness to the principals throughout the play, so the physical presence of the entire cast surrounds the central action as it shifts from consulting-room to living-room, from beach to stable. We are being asked to understand these people, not to make judgements about them. After all, what they do and why they do it seems to be beyond human control. But not perhaps beyond the sport of the gods.